Oral buprenorphine as a novel low-dose induction strategy for individuals with opioid use disorder - Project Summary Abstract
Buprenorphine reduces overdose mortality by up to 70%, making it one of the most critical interventions to
combat the opioid overdose crisis. With the increasing prevalence of illicit fentanyl, patients with opioid use
disorder (OUD) attempting to initiate buprenorphine now routinely report experiencing precipitated withdrawal
despite waiting for withdrawal symptoms to first emerge. In response, clinicians and patients alike are
increasingly recommending a novel strategy called “micro-dosing” or “low-dose” buprenorphine induction, where
a dose significantly lower than the typical 4mg is administered. With this strategy, precipitated withdrawal does
not occur despite buprenorphine is administered before the emergence of withdrawal symptoms. A variety of
low-dose induction protocols have been reported—some use low dose (≤0.5mg) SL buprenorphine, while others
initially use transdermal (Butrans®) or buccal (Belbulca®) formulations. Regardless of the specific approach, the
requirements for a successful low-dose induction appear to be the low initial dose, the slow up-titration of the
buprenorphine, and continuation of the full agonist opioid during the induction. However, these approaches can
be problematic—low-dose SL buprenorphine requires the medication to be cut which is often prohibited in
inpatient settings; transdermal and buccal formulations are costly and often not on formulary; and their use
violates US federal laws that prohibit them to be prescribed to outpatients seeking treatment for OUD. Therefore,
there is an urgent need to research strategies for buprenorphine low-dose inductions that avoid having to cut the
medication, or use prohibited and costly formulations. To meet this need, we propose to study the safety and
feasibility of utilizing orally (PO) administered buprenorphine. Buprenorphine undergoes extensive first-pass
effect when taken PO, hence the bioavailability is estimated to be significantly less than the SL route of 30-50%.
As such, using the existing SL dose formulations (e.g. 8mg) via the oral route may allow low-dose induction
without having to split the medication. However, research on the safety and feasibility of PO buprenorphine is
largely absent. We therefore propose to conduct a two-phased study: in the first phase, we will conduct a
randomized cross-over trial with healthy human volunteers to receive low-dose SL and PO buprenorphine to
determine the pharmacokinetic parameters. The results will inform the dose needed for a successful low-dose
induction using PO buprenorphine. In the second phase, we will conduct a pilot feasibility trial among individuals
with OUD to undergo a low-dose induction using PO buprenorphine in a controlled laboratory setting. Given the
importance of buprenorphine in improving clinical outcomes for individuals with OUD and preventing overdose
deaths, research that aims to identify safe approaches to treatment initiation are urgently needed. Results from
this study will be the basis for a safe, accessible, and evidence-based approach to buprenorphine initiation, and
lay the groundwork for a randomized controlled trial comparing the efficacy of low-dose induction strategies using
PO buprenorphine with standard inductions.